. Experimental
2.1. Instrumentation
Spectrophotometric analysis of HQ was performed with a Lambda 2UV–vis spectrometer of Perkin-Elmer company.
Temperature related observations were carried out with the help of a controlled temperature Water Bath, Model, GMBH D-7633, JulaboHC5,Germany,towhichwasattachedadoublewallflowtypecellhavingathermometerdippedinthetesttubecontaining the analyte solution.